1965 DMW Typhoon
Frame no. PRO 10
While Norton's and BRM's well publicised proposals to build a 'World Beater' Grand Prix 500 in the 1960s never got beyond the drawing board, the small Sedgley-based firm of DMW had a prototype 500cc racer on display at the 1965 Brighton Show: the Typhoon. After a tentative start in the late 1930s, Dawson's Motors Wolverhampton had commenced production of a range of Villiers-powered lightweights in 1950. The firm built its first competition (trials) models in 1952 and introduced a scrambler a couple of years later. Although initially configured for scrambles use with coarse-pitch cylinder finning, the Villiers Starmaker competition engine provided independent manufacturers with a competitive off-the-shelf unit suitable for road racing, and DMW responded with the stylish Hornet, introduced towards the end of 1962. The frame was modelled on that of the scrambler and fitted with telescopic front forks from the Metal Profile Engineering Company, by this time DMW's owners. The production Mk1 of 1963 used the Starmaker engine in fine-finned road racing specification, while future developments included the adoption of a special Alpha bottom-end assembly and Albion five-speed gearbox on the Mk2.
Spurred on by Metal Profile's enthusiastic boss, Harold Knock, DMW created its 500 racer by the simple expedient of joining two Hornet engines together, an arrangement that afforded the prospect of 60-70bhp at a time when a good Manx Norton managed around 52 horsepower. A pair of Alpha crankcase assemblies was used, sandwiching a special straight-cut primary transmission. The latter consisted of a jackshaft in an oil bath, from which drive was taken to a secondary transmission and thence to the Albion five-speed gearbox via a Royal Enfield Interceptor clutch. Ignition contact breakers were mounted at one end of the jackshaft but were later moved to the crankshaft end.
Interposing an extra shaft between the crank and gearbox meant that the Typhoon engine had to run backwards, just like Helmut Fath's URS and the current Yamaha YZF-M1 MotoGP bike. Villiers Starmaker cylinder barrels and 'heads were used for the first of the two prototypes completed - the machine offered here - while the other (currently owned by the National Motorcycle Museum) used Royal Enfield GP5 top-ends and different bore/stroke dimensions. The Typhoon motor went into a lengthened, Hornet-type chassis equipped with MP centre-spring forks, Oldani front brake and DMW rear hub.
In September 1965, the first (Starmaker-based) prototype was track tested by Jack Findlay and Bill Smith at Oulton Park, where its shortcomings became all too apparent. The worst of these was severe vibration, bad enough to affect the riders' vision, and the second was weak brakes. Unable to find a cure for the vibration, Knock abandoned the Typhoon project. Then, in 1967, sidecar racer Peter Gerrish arranged to borrow the Typhoon engine, which was installed in a kneeler outfit. After disappointing outings at Castle Combe and Llandow, the engine was returned to DMW.
When the DMW factory closed in the early 1970s the remains of the first Typhoon prototype were disposed off and disappeared, resurfacing in 1985 when they were purchased from a Hunstanton hotelier by the current vendor, who took on the challenge of making it race-worthy. The brakes were missing so Yamaha TD2 items were used, providing much improved stopping power, and Amal Concentric Mk2 carburettors were fitted to the engine, for which ace two-stroke tuner Brian Woolley designed a new exhaust system based on the Hornet pipe. Curing the endemic vibration proved more difficult; the first move was to realign the crankpins at 360 degrees so that both cylinders fired together, which improved matters but made the machine all but impossible to push-start without assistance. Nevertheless, it was raced in this form by the vendor, Andy Russell and Pete Crew, albeit always handicapped by having to start from the back of the grid. Another who rode the '360-degree' Typhoon was TT-winner Alex George, who worked his way up to 11th place in a race at Snetterton in 1991 before being sidelined with gearbox problems.
The next phase of development saw both 90-degree and 45-degree crankshaft phasing tried, the latter proving to be the answer to the continuing vibration problem. Although the engine was now reliable the Albion gearbox remained problematic, its inability to cope with the power - now up to 70bhp as a result of careful re-porting - leading to frequent retirements. With replacement parts becoming increasingly hard to find, the Typhoon gradually slipped into retirement and was last raced around 8-10 years ago.
The Typhoon remains one of motorcycle racing's more fascinating 'might-have-beens', only needing resources greater than DMW's to realise its full potential. That it could still be one of the fastest of half-litre classic racers seems beyond doubt: 8,500rpm has been seen on the tachometer in top gear, which represents a maximum speed of over 150mph. The past decade has seen increasing activity in the provision of suitable gearboxes for classic racing motorcycles and it seems likely that an experienced specialist firm such as Nova Transmissions would be able to provide one for the Typhoon.
Presented in 'as last raced' condition, this unique and historic British racing motorcycle is offered with Brian Woolley correspondence, various photographs and a quantity of press cuttings and magazine article documenting its history. The original fuel tank is included in the sale.
- Since the catalogue went to press the immediately preceding owner has advised Bonhams that he purchased the DMW Typhoon from Fred Wilson who ran Jackson's Garage in Chorley, Lancashire, and that he has a photograph of the machine as it was when Mr Wilson collected from the factory. He is prepared to send a scan of the photograph to the next owner should the latter so require.